The present invention relates to methods for evaluating microscope images such as from scanning electron microscopes and scanning ion microscopes and relates in particular to a method for evaluating image resolution and a microscope having an evaluation function.
In charged particle microscopes such as scanning electron microscopes (SEM) and scanning ion microscopes (SIM), the related techniques for evaluating image resolution are roughly divided into two methods. One is the gap method disclosed in JP-A-45265/1993 for evaluating image resolution by viewing a microscope image of gold particles deposited by evaporation onto a carbon substrate as a specimen and then finding the minimum visually discernible gap separating the particles at two points as seen on the monitor display of the microscope.
The other is the FFT method as disclosed in JP-A-24640/1999 for evaluating image resolution by frequency analysis of observation image data that was subjected to two-dimensional Fourier transform (FFT).